There has been proposed an image forming apparatus of a type that includes: an electrostatic latent image bearing body such as a photosensitive body having a surface, on which an electrostatic latent image is formed; a toner cartridge containing toner; a developing member such as a developing roller for supplying toner from the toner cartridge to the surface of the electrostatic latent image bearing body, thereby developing the electrostatic latent image into a toner image; and a transfer member such as a transfer roller for transferring the toner image from the surface of the electrostatic latent image bearing body to a recording medium. In the image forming apparatus of this type, after an electrostatic latent image is formed on the surface of the electrostatic latent image bearing body, the developing member supplies the toner from the toner cartridge onto the surface of the electrostatic latent image bearing body, thereby developing the latent image. Then, the transfer member transfers the toner image from the surface of the electrostatic latent image bearing body to a recording medium. As a result, an image corresponding to the electrostatic latent image is formed on the recording medium.
In the image forming apparatus of this type, a bias voltage has to be applied to various components, such as the developing roller, the transfer roller, and a charger. The charger is for applying an electric charge uniformly to the photosensitive body.
Japanese Unexamined Patent Application Publication No. 11-327288 proposes applying, from the main body of the image forming apparatus, bias voltages to a cartridge, in which the photosensitive body, the developing roller and the transfer roller are mounted.
Japanese Unexamined Patent Application Publication No. 11-305629 proposes providing an electrode on one end of a cartridge that installs a developing roller therein, and providing another electrode in the main body of the image forming apparatus. These electrodes are brought into abutment contact with each other when the cartridge is set in the main body.